This invention relates to printing indexers used for multicolor printing. More particularly, this invention relates to an improved pallet assembly which provides full surface, two-sided printing on various types of fabrics and garments.
Various forms of semi-automatic printing apparatus and indexers for printing multiple color images on fabric material are described in the prior art. Typically, reference may be had to U.S. Pat. Nos. 2,229,346; 2,694,973; 3,416,440; Re. 29,160; and 4,099,460. Generically, this class of equipment is characterized by a number of fixed pallets oriented radially around a vertical axis. In operation, garments or other fabric material to receive print images are placed on pallets so that the upper surface of the fabric is exposed for printing. The pallets are then "indexed" around the vertical axis to individual print stations located around the periphery of the printing indexer.
Located at each of the print stations is an appropriate printing device, e.g., a screen printer, whose operation is synchronized with the movement of the indexer. As would be understood by one skilled in the art, once each pallet is properly indexed, the printers are activated such that a screen or similar pattern transferring device is positioned onto the print receiving medium on the pallet. With a screen printer an applicator in the form of a roller or squeegee then contacts the screen and traverses the surface thereof causing the print image to be transferred onto the garment or other fabric located on the pallet. After the applicator completes its travel, the printing machine disengages the pallet by lifting both the applicator and screen from the print receiving medium, and the pallet then proceeds to the next print station for further printing.
In order for a pallet assembly to function properly as a garment holder, it must be shaped generally to the configuration of the garment which it will support. In this manner, the garment may be slipped over the pallet exposing a single surface for printing. The other side of the garment is protected by the pallet from any "strike through" during the printing operation.
In addition, the pallet must be fixed in relationship to the indexing drive mechanism during the print cycle so as to ensure accurate and positive indexing and print registration from one print station to the next. To accomplish this, past pallet designs have relied upon rigid connections which immobilize the pallet relative to the drive mechanism.
Although these prior art mechanisms operate satisfactorily, they suffer from several major disadvantages. Since the pallet is fixed in relationship to the drive mechanism, only the originally exposed surface is available for printing. If an imprint is desired on the opposite side of the garment, the garment must be removed from the pallet and repositioned back onto the pallet exposing the new surface. This manual operation is not only time-consuming and difficult to perform accurately, but in many instances the operator is required to handle the printed surface prior to complete drying frequently resulting in smearing or otherwise damaging the printed design.
Another problem inherent in past designs of the pallet assembly involves the actual printing operation. As discussed above, printing is accomplished at each print station by placing a screen containing the image to be transferred onto the fabric on the pallet. A flexible squeegee is then drawn across the length of the screen imprinting the fabric with the print image. Heretofore, the squeegee was selected no wider than the pallet so as not to overlap the side edges of the pallet. Overlapping the side edges of the pallet has tended to wear and damage the screen material and so was to be avoided. But this has placed a limitation on the width of the printable image and has prevented printing all the way to the edge of the fabric or garment.